线粒体DNA G13513A突变所致线粒体脑肌病伴高乳酸血症和脑卒中样发作/Leigh重叠综合征

目的 报道1例线粒体DNA G13513A点突变所致线粒体脑肌病伴高乳酸血症和脑卒中样发作(MELAS)/Leigh重叠综合征的临床、影像学、神经病理学改变特点.方法 患者为22岁女性,反复出现头痛、视力下降和肢体抽动11年,因癫疴持续状态而死亡.之前多次MRI检查发现大脑皮质大片长T1长T2异常信号,病灶从枕叶开始,逐渐波及顶叶,疾病后期累及双侧基底节区及脑干灰质核团.对患者进行脑局部尸体解剖检查,取肌肉标本进行线粒体基因检查.结果 各个脑叶皮质以及双侧纹状体和中脑四叠体可见多灶性层样分布的海绵样改变,出现胶质增生、毛细血管内皮细胞增生以及较多单核细胞反应,其中双侧枕叶和顶叶的皮质全层以及皮质下白质被严重累及.基因检查显示线粒体还原型烟酰胺腺嘌呤二核苷酸脱氢酶5基因存在G13513A点突变.结论 MELAS/Leigh重叠综合征的临床表现以皮质损害为主,影像学改变提示病变先累及大脑皮质,而后累及脑干和基底节区,出现海绵样改变伴随毛细血管增生.

Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes/Leigh overlap syndrome caused by mutation of mitochondrial DNA G13513A

Objective To describe the chnical, neuroimagine, pathological and genetic features in a case with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)/Leigh overlap syndrome.Methods The ease was a 22-year-old woman with recurrent headache, loss of visual acuity and general seizures over 11 years.MRI demonstrated symmetrical high T2-weighted signals in occipital and parietal lobes, in the late stage of the disease, the above imagine changes on MRJ were also shown in the bilateral basal ganglion and brainstem.She died of status epilepticus at age of 22.Brain autopsy and mitochondrial DNA (mtDNA) analysis were performed in the patient.Results The main neuropathological findings were muhifocal and lamilar spongiform in the cortex of the whole brain, the basal ganglion and middle brain.Gliosis, macrophagie reaction and capillary endothelial proliferation were observed in these areas.All 6 layers of the cortex and subcortical white matter in occipital and parietal lobes were severely affected.GI3513A mutation was found in the gene of mitochondria encoded NADH dehydrogenase subunit 5 (MTNDS).Conclusions MELAS/Leigh overlap syndrome presents the symptoms predominantly affecting the cerebral cortex.Neuroimagines suggested that the lesion initially involves the cerebral cortex and in the late stage implicates the basal ganglion and the brainstem, possibly caused by pathological changes of spongiform with capillary proliferation in these areas.